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CASE SUMMARY

A 21-year-old woman was admitted to the hospital with acute abdominal
distension and pain for the last 24 hours. Although she had been having
intermittent vomiting, constipation and sub-acute abdominal pain for the
last two years, there was an acute exacerbation of symptoms with
episodes of acute abdominal pain, distension and vomiting for last seven
days. The patient had been on medical treatment for intermittent
abdominal distension, pain and vomiting by local physicians but there
was no history of hospital admission. She denied any bowel movements for
the last five days. Physical examination on admission revealed marked
abdominal distension. There was marked tenderness to palpation and
decreased bowel sounds. Patient had tachycardia and increased blood
pressure at time of examination. The remaining physical examination and
laboratory data were normal.

IMAGING FINDINGS

Abdominal radiographs (erect and supine, Figures 1A and B) revealed
large bowel dilatation with large mixed density lesion with interspersed
air foci within, giving mottled appearance at the distal end of the
dilated left gas-filled colonic shadow. No free intraperitoneal air was
seen. Then, upon physician request as per protocol, emergency abdominal
ultrasonography was done. On ultrasonography, a well-defined lobulated
hyper-echoic lesion with strong posterior dirty shadowing was seen
impacted at proximal sigmoid colon with significant dilatation of
proximal large colon extending up to caecum (Figures 2A and B). No
significant increased peristalses were seen. Small-bowel loops were
collapsed. On the basis of X-rays and ultrasonographic findings, we gave
possibilities of colonic bezoar/faecolith; however, bezoar was the
first possibility given, as the density of the lesion was less than
calcification on plain radiograph, and the posterior acoustic shadow on
ultrasonography was somewhat dirty (like that of air). Considering
patient’s acute condition and radiological diagnosis, patient was
operated on. Per operation, large bowel dilatation was discovered with
transition at sigmoid level and when it was opened by longitudinal
incision, a large lobulated ball of cloth fibers interspersed with
faecal matter (Figures 3A and B) was seen impacted at proximal sigmoid
colon, which was removed operatively and the colonic incision was closed
transversely. Post-operative period was uneventful. And when elicited,
there was a history of the patient eating cloth fibers for the previous
three years, for which psychiatric evaluation was advised. Psychiatric
evaluation found the patient to be mentally disturbed for the past few
years due to marital disharmony. She has been undergoing treatment for
psychiatric illness along with routine follow-up in the surgical
outpatient department.

DIAGNOSIS

DISCUSSION

The word bezoar is derived from the Persian word “padzahr,” which means
antidote. The bezoars are concretions or masses of foreign material seen
in different locations of gastrointestinal tract.1,2,3,4
They are classified into different types: Phytobezoar, Trichobezoar,
Lactobezoar, and Hard concretions. The phytobezoars are composed of
fibrous matter, such as skin, seeds, vegetable, and fruit fibers. The
trichobezoars, or hairballs, are composed of masses of hair and decaying
food materials. The lactobezoar contains undigested milk curds and the
hard concretions are inorganic masses or calculi usually containing
calcium. Recently, many iatrogenic gastrointestinal lesions, including
bezoars secondary to medications (Pharmacobezoar) have been reported.5-7
Although bezoar formation may occur in individuals with normal
gastrointestinal anatomy and physiology, patients with altered
gastrointestinal anatomy and/or motility are at increased risk for
developing bezoars. Bezoar formation has also been described in patients
with coexistent illnesses affecting gastrointestinal motility, such as
diabetes mellitus, Guillain-Barre syndrome, myotonic dystrophy, and
hypothyroidism.8 Other medical conditions associated with
increased risk for bezoar development include cystic fibrosis,
intrahepatic cholestasis, and renal failure. In addition, patients with
psychiatric illnesses are at an increased risk for bezoar formation.9
Most bezoars are formed in the stomach, and may cause intestinal or
esophageal obstruction after breakup and migration of the gastric
masses. Primary colonic bezoars are extremely rare. Review of literature
revealed only two reports of primary colonic bezoar causing large bowel
obstruction.10,11 Conventional abdominal radiographs are
usually enough to detect bowel obstruction; however, its causation due
to bezoar is difficult to diagnose on plain radiographs alone. The
bezoars could be identified in only 10% of patients from radiographs
alone, as reported by Verstanding et al.12 The bezoar on
plain radiographs is seen as ill-defined heterogeneous mix radiodensity
lesion with interspersed air foci within giving mottled appearance
usually seen at the transition point of dilated bowel loops. They can be
easily mistaken for an abscess or the presence of faeces in the colon.
On barium studies, bezoar produces a heterogeneous intraluminal filling
defect with interstices filled with barium. Sonography is routinely used
to examine both patients with nonspecific acute abdominal pain and
those with signs of bowel obstruction on radiographs. Many authors have
shown ultrasonography to be of excellent sensitivity and specificity in
diagnosing intestinal obstruction.13 As per literature,
sonographic visualization of an intraluminal mass with a hyperechoic
arc-like surface and a marked acoustic shadow is suggestive of a bezoar.14,15
On the basis of this characteristic image, we also suspected the
presence of a bezoar before surgery in our case, which was proved
preoperatively. Differentials include heterogeneous intraluminal masses
causing intestinal obstruction. Bezoar-induced obstruction should be
distinguished from gallstone ileus because bezoars produce the same
sonographic image as ectopic lithiasis.16 Faecal material in
the colon can also simulate the image of a bezoar, particularly in the
presence of concretions. Many studies have shown diagnostic accuracy of
CT in evaluating bowel obstruction in terms of cause, level, and degree
of intestinal obstruction.17, 18 Oral contrast medium is
unnecessary in most of the cases as in the presence of high-degree
obstruction, the bowel loops are usually filled with fluid and air,
which provide excellent contrast. As per literature in most of the
cases, the appearance of bowel obstructing bezoars on scans is quite
characteristic for diagnosis.19–22 As per published
characteristic images in the literature, they usually reveal a
well-defined oval intraluminal mass with air bubbles retained within the
interstices and proximal dilated bowel loops.

CONCLUSION

The existence of a bezoar as the underlying cause of intestinal
obstruction should always be considered in differentials of intraluminal
bowel masses causing intestinal obstruction. In contrast to clinical
examination, radiological modalities always help physicians rapidly
diagnose bezoar-induced intestinal obstruction and prevent complication.
However, plain radiography and sonographic images of bezoar can be
confused with other conditions; the image of a gastrointestinal
bezoar—an intraluminal mass showing mottled air pattern—is quite
characteristic.

About the Author

Prepared by Dr. Chiranjeev Kumar Gathwal while an Assistant Professor of
Radiology; Dr. Monika B Gathwal while as an Assistant Professor of
Pathology; Dr. Kulvinder Singh, while an Associate Professor of
Radiology; and Dr. Anubhav Arya while a Senior Resident of Surgery at
BPS Government Medical College for Women, Khanpur Kalan Sonepat
(Haryana), India.